The present invention relates generally to an adapter assembly for attaching a control unit to an electrical device such as a heater, and more particularly, to an adapter assembly that provides easy installation and orientation of the control unit.
The heating of tanks and pipes is a common industrial practice that has many applications. Heating may be required to maintain a certain viscosity of heavy oils or resins that allow them to be readily pumped. Heating may also prevent crystalline precipitation or freezing during a process, or may simply facilitate the process itself.
Screw plug heaters with extending heating elements are used to heat fluids in a tank or reservoir. The heating elements are inserted through a threaded bore in the tank wall, and the screw plug of the heater is tightened within the bore. In this way, the heating elements extend within the tank, the screw plug seals the opening, and the electrical terminals for the heating elements lie outside the tank barrier.
It is common to connect a control unit for the heater directly outside the tank. In some instance, the control unit is attached directly to the heater. A conventional adapter assembly for attaching a control unit to a screw plug heater 10 is depicted in FIGS. 1A-1D. The solution uses a series of flanges and connection rings to attach the control unit to the screw plug heater 10. The screw plug heater 10 is threaded into a barrier or wall (not shown) so that the heating element 12 extends within a tank or reservoir (not shown). The terminals 14 of the heater 10 extend outside the barrier for connection to terminals 16 of a control unit.
To form the adapter assembly, the opposite ends of a mechanical tube 20 are fitted with a screw plug ring adapter 30 and a flange ring 40. The screw plug ring adapter 30 and flange ring 40 may be fixed to the ends of the mechanical tube 20 by welds or a strong metallic adhesive. The end of the mechanical tube 20 having the ring adapter 30 is used to connect the mechanical tube 20 to the screw plug heater 10. The end of the mechanical tube 20 having the flange ring 40 is used to connect the mechanical tube 20 to the back wall 60 of a control unit.
A clamp ring 50 is also used in the assembly. The clamp ring 50 has a hole 52 that slides over the exterior surface 22 of the tube 20. Accordingly, the hole 52 of the clamp ring 50 has a diameter slightly greater than the exterior surface 22 of the mechanical tube 20. The outer diameter of the clamp ring 50 is greater than the outer diameter of the flange ring 40.
After sliding the clamp ring 50 on the mechanical tube 20, the screw plug ring adapter 30 may be installed on the screw plug heater 10. The ring adapter 30 has an opening 32 to accommodate the terminals 14 of the screw plug heater 10. The ring adapter 30 is attached to the screw plug heater 10 by inserting screws 34 into one of two sets of holes 36, 38 of the ring adapter 30. The two sets of holes 36, 38 allow the adapter 30 to attach to different sized screw plug heaters.
With the mechanical tube 20 attached to the screw plug heater 10, the tube 20 is then attached to the back wall 60 of the control unit. The back wall 60 of the control unit has an opening 62 to accommodate wires of the control unit terminals 16. The back wall 60 is placed against the flange ring 40. Several bolts 64 are then inserted through access holes 66 in the back wall 60 and into holes 54 of the clamp ring 50. As a result, the flange ring 40 is sandwiched between the back wall 60 of the control unit and the clamp ring 50. The control unit hangs on the screw plug heater 10.
Several inefficiencies exist with conventional adapter assemblies. For example, the location of the access holes 66 in the back panel 60 of the control unit restricts the placement of internal components within the control unit. This results in ineffective use of space within the control unit. Moreover, installation and orientation of the control unit is difficult. The control unit must be opened to insert or remove bolts 64. Aligning the holes 54 in the clamp ring 50 with the access holes 66 in the back wall 60 of the control unit makes orientation of the control unit cumbersome.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
To that end, the present invention includes an adapter assembly for connecting a control unit to a heater. The control unit has wires that connect to terminals on the heater. The adapter assembly includes a first tubular body portion, a second tubular body portion and at least one locking bolt. The first tubular body portion is attached to the heater. The second tubular body portion is attached to the control unit. At least a portion of the first tubular body portion is retained inside the second tubular body portion. The locking bolt attaches the second tubular body portion to the first tubular body portion by inserting through a hole in the second tubular body portion.
The hole in the second tubular body portion may be a slot that enables the control unit to be radially oriented with respect to the first tubular body portion when installing and attaching the second tubular body portion to the first tubular body portion. The first tubular body portion may have threaded holes circumscribed on the outer surface of the first tubular body portion to receive the locking bolt. The first tubular body portion may also have locking wells circumscribed on the outer surface of the first tubular body portion to receive the locking bolt.
The present invention also includes an adapter assembly with the reverse attachments. Specifically, the first tubular body portion (retained inside the second tubular body portion) may be attached to the control unit instead of the heater. In this case, the second tubular body portion is attached to the heater.
In another embodiment, the present invention is an adapter assembly for connecting a first unit to a second unit. The first unit has an electrical terminal connecting to a wire in the second unit. The adapter assembly includes a first conduit and a second conduit. There is a means for attaching the first conduit to the first unit and a means for attaching the second conduit to the second unit. Moreover, the adapter assembly has a means for radially orienting the first unit with respect to the second unit and a means for attaching the first conduit to the second conduit once an orientation is selected.
In yet another embodiment, the present invention includes a method for joining a control unit having power wires to an electrical device having terminals. The method includes the steps of: attaching a first conduit to the control unit so that the power wires extend within the first conduit; attaching a second conduit to the electrical device so that the terminals of the electrical device extend within the second conduit; connecting the power wires of the control unit to the terminals of the electrical device; inserting the second conduit into the first conduit; orienting the control unit radially with respect to the electrical device to a selected orientation; and maintaining the selected orientation by fastening the first conduit to the second conduit. The fastening may be done in a variety of ways including inserting a bolt through a locking slot in the first conduit and threading the bolt into a locking hole in the second conduit. The method may further include changing the attaching steps so that the first conduit is attached to the electrical device and the second conduit is attached to the control unit.
Another embodiment of the present invention is a kit containing parts of an adapter assembly for a heater. The kit includes: a first conduit capable of being attached to a heater; a second conduit capable of being attached to a control unit, the first conduit having a diameter so that it is capable of being retained inside the second conduit; and a plurality of locking bolts for attaching the second conduit to the first conduit.
The above summary of the present invention is not intended to represent each embodiment, or every aspect of the present invention. This is the purpose of the figures and detailed description that follows.